A Miniaturized, Broadband MMIC Balanced Mixer Module

This paper describes a miniaturized MMIC balanced mixer module composed of a 4-gate GaAs FET and slotline series T junction, where the combiner and dividers, in phase and out of phase, are unified in the electrode locations of the 4-gate GaAs FET to provide all of the fundamental functions required for a balanced mixer. Using this module, an 8-20GHz balanced mixer is designed and fabricated in a 0.7mm × 1.1mm MMIC chip. This mixer has a conversion loss of 8.5±1.5dB and an LO-RF port isolation of better than 35dB between 8 and 20GHz.